This invention relates to a recording/reproducing apparatus and a recording/reproducing method.
Abstract of JP-A-2007-521606 describes as follows. “The invention relates to an information recording medium having a plurality of information recording layers and each of the information recording layers has an OPC area for obtaining an optimum recording condition. The OPC areas of odd-numbered information recording layers in a light incidence direction and the OPC areas of even-numbered information recording layers adjacent to the former are arranged alternately so as not come into contact with one another and an area of the OPC area of each recording information layer that can be used in practice is variable depending on the environment of use of each information recording layer. In consequence, the area of the information recording layer can be used efficiently while influences on other information recording layers are reduced to minimum even when optimum power control is made in the OPC area provided to each information recording layer”.